//////////////////////////////////////////////////////////////
// From JAVA PROGRAMMING: FROM THE BEGINNING, by K. N. King //
// Copyright (c) 2000 W. W. Norton & Company, Inc.          //
// All rights reserved.                                     //
// This program may be freely distributed for class use,    //
// provided that this copyright notice is retained.         //
//                                                          //
// PickColor.java (Chapter 12, page 527)                    //
//////////////////////////////////////////////////////////////

// Allows the user to pick a color by moving three scrollbars

import java.awt.*;
import java.awt.event.*;

// Driver class
public class PickColor {
    public static void main(String[] args) {
        Frame f = new PickColorFrame("Pick Color");
        f.setSize(150, 200);
        f.setVisible(true);
    }
}

// Frame class
class PickColorFrame extends Frame {
    private Label redLabel = 
        new Label("Red = 128", Label.CENTER);
    private Label greenLabel = 
        new Label("Green = 128", Label.CENTER);
    private Label blueLabel = 
        new Label("Blue = 128", Label.CENTER);
    private Scrollbar redBar = 
        new Scrollbar(Scrollbar.HORIZONTAL, 128, 1, 0, 256);
    private Scrollbar greenBar = 
        new Scrollbar(Scrollbar.HORIZONTAL, 128, 1, 0, 256);
    private Scrollbar blueBar = 
        new Scrollbar(Scrollbar.HORIZONTAL, 128, 1, 0, 256);

    // Constructor
    public PickColorFrame(String title) {
        // Set title, background color, and layout
        super(title);
        setBackground(new Color(128, 128, 128));
        setLayout(new GridLayout(6, 1));

        // Create scrollbar listener
        ScrollbarListener listener = new ScrollbarListener();

        // Add red scrollbar and label to frame; attach
        // listener to scrollbar
        add(redBar);
        redBar.addAdjustmentListener(listener);
        add(redLabel);

        // Add green scrollbar and label to frame; attach
        // listener to scrollbar
        add(greenBar);
        greenBar.addAdjustmentListener(listener);
        add(greenLabel);

        // Add blue scrollbar and label to frame; attach
        // listener to scrollbar
        add(blueBar);
        blueBar.addAdjustmentListener(listener);
        add(blueLabel);

        // Attach window listener
        addWindowListener(new WindowCloser());
    }

    // Listener for all scrollbars
    class ScrollbarListener implements AdjustmentListener {
        public void adjustmentValueChanged(AdjustmentEvent evt) {
            int red = redBar.getValue();
            int green = greenBar.getValue();
            int blue = blueBar.getValue();

            redLabel.setText("Red = " + red);
            greenLabel.setText("Green = " + green);
            blueLabel.setText("Blue = " + blue);

            Color newColor = new Color(red, green, blue);
            redLabel.setBackground(newColor);
            greenLabel.setBackground(newColor);
            blueLabel.setBackground(newColor);
        }
    }

    // Listener for window
    class WindowCloser extends WindowAdapter {
        public void windowClosing(WindowEvent evt) {
            System.exit(0);
        }
    }
}